The present invention relates to a pumping ejector with a nozzle which uses pressurised steam as the entrainment fluid for another fluid to be pumped.
Numerous constructions of apparatus of this type are known, particularly with reference to their use for conveying dangerous and in particular radioactive fluids where, unlike pumps, said ejectors have no rotating parts and are therefore particularly suitable because they do not require the fitting of special sealing means of the type which have to be provided between the impellers of pumps and their drive motors.
In certain nuclear installations ejectors have been used whose construction and arrangement are such that it is easy to disassemble the nozzle for repair and maintenance, whereby said disassembly can take place without any danger of radioactive contamination of the environment outside a protective cell which in its wall carries the exchanger body. In particular such an ejector has been described and claimed in French Pat. No. 2,122,640 in the name of the commissariat a l'Energie Atomique.
In the case of such ejectors two constructional solutions can be envisaged, depending on whether the steam is supplied inside or outside the protective cell, the ejector body being in all cases carried by a supporting block fitted in the wall of the cell or anchored in the concrete which generally constitutes the latter. However, due to the dangerous nature of the fluids conveyed it is generally difficult in constructions of this type to gain access to the pipes connected to the ejector body upstream and downstream of the nozzle fitted in said body and by means of which the acceleration of the pumping steam is obtained. Due to the suspended particles contained in the pumped fluid or its inherent viscosity in many cases said fluid may obstruct and even totally block the pipes, thus making the ejector unusable.